On December 29, 1998, the FAA issued emergency AD 99-01-12, which is applicable to certain EMBRAER Model EMB-145 series airplanes.
The Departmento de Aviacao Civil (DAC), which is the airworthiness authority for Brazil, recently notified the FAA that an unsafe condition may exist on certain EMBRAER Model EMB-145 series airplanes. The DAC advises that, during a flight test of a similar airplane model, equipped with a Honeywell Primus 1000 Integrated Avionics System, the pitch trim monitoring subsystem experienced an internal malfunction. The cause of the failure of this system has been attributed to a software error, which resulted in failure of the trim monitoring subsystem to detect a trim malfunction. This condition, if not corrected, could cause undetected autopilot trim runaway, which could result in reduced controllability of the airplane, uncommanded autopilot disconnect, and excessive altitude loss. If these conditions occur at low altitude, control of the airplane could be unrecoverable.
Explanation of Relevant Service Information
EMBRAER has issued Alert Service Bulletin S.B. 145-31-A010, dated December 15, 1998, which describes procedures for installation of certain warning placards on the left and right sides of the cockpit glareshield panel to prohibit use of the autopilot below 1,500 feet above ground level (AGL). The DAC classified this alert service bulletin as mandatory and issued Brazilian Emergency Airworthiness Directive 98-12-01, dated December 21, 1998, in order to assure the continued airworthiness of these airplanes in Brazil.
FAA's Conclusions
This airplane model is manufactured in Brazil and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DAC, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.
Explanation of the Requirements of the Rule
Since the unsafe condition described is likely to exist or develop on other airplanes of the same type design registered in the United States, the FAA issued emergency AD 99-01-12 to prevent failure of the pitch trim system, which could cause undetected autopilot trim runaway, and consequent reduced controllability of the airplane, uncommanded autopilot disconnect, and excessive altitude loss.
The AD requires installation of certain warning placards on the left and right sides of the cockpit glareshield panel to prohibit autopilot below 1,500 feet AGL. The installation of the placard is required to be accomplished in accordance with the alert service bulletin described previously.
In addition, the FAAhas determined that a revision to the Airplane Flight Manual (AFM) is necessary to ensure that the Limitations Section of the AFM is changed to provide the flight crew with updated procedures prohibiting the use of the autopilot below 1,500 feet AGL, emergency procedures for pitch trim runaway, and abnormal procedures for autopilot trim failure and stabilizer out of trim.
This amendment is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.
Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual notices issued on December 29, 1998, to all known U.S. owners and operators of certain EMBRAER Model EMB-145 series airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.
Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 98-NM-386-AD." The postcard will be date stamped and returned to the commenter.
Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels ofgovernment. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: